libavformat/gxf.c

   1 /*
   2  * GXF demuxer.
   3  * Copyright (c) 2006 Reimar Doeffinger
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/common.h"
  23 #include "avformat.h"
  24 #include "gxf.h"
  25
  26 struct gxf_stream_info {
  27     int64_t first_field;
  28     int64_t last_field;
  29     AVRational frames_per_second;
  30     int32_t fields_per_frame;
  31 };
  32
  33 /**
  34  * \brief parses a packet header, extracting type and length
  35  * \param pb ByteIOContext to read header from
  36  * \param type detected packet type is stored here
  37  * \param length detected packet length, excluding header is stored here
  38  * \return 0 if header not found or contains invalid data, 1 otherwise
  39  */
  40 static int parse_packet_header(ByteIOContext *pb, GXFPktType *type, int *length) {
  41     if (get_be32(pb))
  42         return 0;
  43     if (get_byte(pb) != 1)
  44         return 0;
  45     *type = get_byte(pb);
  46     *length = get_be32(pb);
  47     if ((*length >> 24) || *length < 16)
  48         return 0;
  49     *length -= 16;
  50     if (get_be32(pb))
  51         return 0;
  52     if (get_byte(pb) != 0xe1)
  53         return 0;
  54     if (get_byte(pb) != 0xe2)
  55         return 0;
  56     return 1;
  57 }
  58
  59 /**
  60  * \brief check if file starts with a PKT_MAP header
  61  */
  62 static int gxf_probe(AVProbeData *p) {
  63     static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
  64     static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
  65     if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
  66         !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
  67         return AVPROBE_SCORE_MAX;
  68     return 0;
  69 }
  70
  71 /**
  72  * \brief gets the stream index for the track with the specified id, creates new
  73  *        stream if not found
  74  * \param stream id of stream to find / add
  75  * \param format stream format identifier
  76  */
  77 static int get_sindex(AVFormatContext *s, int id, int format) {
  78     int i;
  79     AVStream *st = NULL;
  80     for (i = 0; i < s->nb_streams; i++) {
  81         if (s->streams[i]->id == id)
  82             return i;
  83     }
  84     st = av_new_stream(s, id);
  85     if (!st)
  86         return AVERROR(ENOMEM);
  87     switch (format) {
  88         case 3:
  89         case 4:
  90             st->codec->codec_type = CODEC_TYPE_VIDEO;
  91             st->codec->codec_id = CODEC_ID_MJPEG;
  92             break;
  93         case 13:
  94         case 15:
  95             st->codec->codec_type = CODEC_TYPE_VIDEO;
  96             st->codec->codec_id = CODEC_ID_DVVIDEO;
  97             break;
  98         case 14:
  99         case 16:
 100             st->codec->codec_type = CODEC_TYPE_VIDEO;
 101             st->codec->codec_id = CODEC_ID_DVVIDEO;
 102             break;
 103         case 11:
 104         case 12:
 105         case 20:
 106             st->codec->codec_type = CODEC_TYPE_VIDEO;
 107             st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
 108             st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
 109             break;
 110         case 22:
 111         case 23:
 112             st->codec->codec_type = CODEC_TYPE_VIDEO;
 113             st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
 114             st->need_parsing = AVSTREAM_PARSE_HEADERS; //get keyframe flag etc.
 115             break;
 116         case 9:
 117             st->codec->codec_type = CODEC_TYPE_AUDIO;
 118             st->codec->codec_id = CODEC_ID_PCM_S24LE;
 119             st->codec->channels = 1;
 120             st->codec->sample_rate = 48000;
 121             st->codec->bit_rate = 3 * 1 * 48000 * 8;
 122             st->codec->block_align = 3 * 1;
 123             st->codec->bits_per_coded_sample = 24;
 124             break;
 125         case 10:
 126             st->codec->codec_type = CODEC_TYPE_AUDIO;
 127             st->codec->codec_id = CODEC_ID_PCM_S16LE;
 128             st->codec->channels = 1;
 129             st->codec->sample_rate = 48000;
 130             st->codec->bit_rate = 2 * 1 * 48000 * 8;
 131             st->codec->block_align = 2 * 1;
 132             st->codec->bits_per_coded_sample = 16;
 133             break;
 134         case 17:
 135             st->codec->codec_type = CODEC_TYPE_AUDIO;
 136             st->codec->codec_id = CODEC_ID_AC3;
 137             st->codec->channels = 2;
 138             st->codec->sample_rate = 48000;
 139             break;
 140         // timecode tracks:
 141         case 7:
 142         case 8:
 143         case 24:
 144             st->codec->codec_type = CODEC_TYPE_DATA;
 145             st->codec->codec_id = CODEC_ID_NONE;
 146             break;
 147         default:
 148             st->codec->codec_type = CODEC_TYPE_UNKNOWN;
 149             st->codec->codec_id = CODEC_ID_NONE;
 150             break;
 151     }
 152     return s->nb_streams - 1;
 153 }
 154
 155 /**
 156  * \brief filters out interesting tags from material information.
 157  * \param len length of tag section, will be adjusted to contain remaining bytes
 158  * \param si struct to store collected information into
 159  */
 160 static void gxf_material_tags(ByteIOContext *pb, int *len, struct gxf_stream_info *si) {
 161     si->first_field = AV_NOPTS_VALUE;
 162     si->last_field = AV_NOPTS_VALUE;
 163     while (*len >= 2) {
 164         GXFMatTag tag = get_byte(pb);
 165         int tlen = get_byte(pb);
 166         *len -= 2;
 167         if (tlen > *len)
 168             return;
 169         *len -= tlen;
 170         if (tlen == 4) {
 171             uint32_t value = get_be32(pb);
 172             if (tag == MAT_FIRST_FIELD)
 173                 si->first_field = value;
 174             else if (tag == MAT_LAST_FIELD)
 175                 si->last_field = value;
 176         } else
 177             url_fskip(pb, tlen);
 178     }
 179 }
 180
 181 /**
 182  * \brief convert fps tag value to AVRational fps
 183  * \param fps fps value from tag
 184  * \return fps as AVRational, or 0 / 0 if unknown
 185  */
 186 static AVRational fps_tag2avr(int32_t fps) {
 187     extern const AVRational ff_frame_rate_tab[];
 188     if (fps < 1 || fps > 9) fps = 9;
 189     return ff_frame_rate_tab[9 - fps]; // values have opposite order
 190 }
 191
 192 /**
 193  * \brief convert UMF attributes flags to AVRational fps
 194  * \param fps fps value from flags
 195  * \return fps as AVRational, or 0 / 0 if unknown
 196  */
 197 static AVRational fps_umf2avr(uint32_t flags) {
 198     static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
 199         {25, 1}, {30000, 1001}};
 200     int idx =  av_log2((flags & 0x7c0) >> 6);
 201     return map[idx];
 202 }
 203
 204 /**
 205  * \brief filters out interesting tags from track information.
 206  * \param len length of tag section, will be adjusted to contain remaining bytes
 207  * \param si struct to store collected information into
 208  */
 209 static void gxf_track_tags(ByteIOContext *pb, int *len, struct gxf_stream_info *si) {
 210     si->frames_per_second = (AVRational){0, 0};
 211     si->fields_per_frame = 0;
 212     while (*len >= 2) {
 213         GXFTrackTag tag = get_byte(pb);
 214         int tlen = get_byte(pb);
 215         *len -= 2;
 216         if (tlen > *len)
 217             return;
 218         *len -= tlen;
 219         if (tlen == 4) {
 220             uint32_t value = get_be32(pb);
 221             if (tag == TRACK_FPS)
 222                 si->frames_per_second = fps_tag2avr(value);
 223             else if (tag == TRACK_FPF && (value == 1 || value == 2))
 224                 si->fields_per_frame = value;
 225         } else
 226             url_fskip(pb, tlen);
 227     }
 228 }
 229
 230 /**
 231  * \brief read index from FLT packet into stream 0 av_index
 232  */
 233 static void gxf_read_index(AVFormatContext *s, int pkt_len) {
 234     ByteIOContext *pb = s->pb;
 235     AVStream *st = s->streams[0];
 236     uint32_t fields_per_map = get_le32(pb);
 237     uint32_t map_cnt = get_le32(pb);
 238     int i;
 239     pkt_len -= 8;
 240     if (map_cnt > 1000) {
 241         av_log(s, AV_LOG_ERROR, "too many index entries %u (%x)\n", map_cnt, map_cnt);
 242         map_cnt = 1000;
 243     }
 244     if (pkt_len < 4 * map_cnt) {
 245         av_log(s, AV_LOG_ERROR, "invalid index length\n");
 246         url_fskip(pb, pkt_len);
 247         return;
 248     }
 249     pkt_len -= 4 * map_cnt;
 250     av_add_index_entry(st, 0, 0, 0, 0, 0);
 251     for (i = 0; i < map_cnt; i++)
 252         av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
 253                            i * (uint64_t)fields_per_map + 1, 0, 0, 0);
 254     url_fskip(pb, pkt_len);
 255 }
 256
 257 static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
 258     ByteIOContext *pb = s->pb;
 259     GXFPktType pkt_type;
 260     int map_len;
 261     int len;
 262     AVRational main_timebase = {0, 0};
 263     struct gxf_stream_info si;
 264     int i;
 265     if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
 266         av_log(s, AV_LOG_ERROR, "map packet not found\n");
 267         return 0;
 268     }
 269     map_len -= 2;
 270     if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
 271         av_log(s, AV_LOG_ERROR, "unknown version or invalid map preamble\n");
 272         return 0;
 273     }
 274     map_len -= 2;
 275     len = get_be16(pb); // length of material data section
 276     if (len > map_len) {
 277         av_log(s, AV_LOG_ERROR, "material data longer than map data\n");
 278         return 0;
 279     }
 280     map_len -= len;
 281     gxf_material_tags(pb, &len, &si);
 282     url_fskip(pb, len);
 283     map_len -= 2;
 284     len = get_be16(pb); // length of track description
 285     if (len > map_len) {
 286         av_log(s, AV_LOG_ERROR, "track description longer than map data\n");
 287         return 0;
 288     }
 289     map_len -= len;
 290     while (len > 0) {
 291         int track_type, track_id, track_len;
 292         AVStream *st;
 293         int idx;
 294         len -= 4;
 295         track_type = get_byte(pb);
 296         track_id = get_byte(pb);
 297         track_len = get_be16(pb);
 298         len -= track_len;
 299         gxf_track_tags(pb, &track_len, &si);
 300         url_fskip(pb, track_len);
 301         if (!(track_type & 0x80)) {
 302            av_log(s, AV_LOG_ERROR, "invalid track type %x\n", track_type);
 303            continue;
 304         }
 305         track_type &= 0x7f;
 306         if ((track_id & 0xc0) != 0xc0) {
 307            av_log(s, AV_LOG_ERROR, "invalid track id %x\n", track_id);
 308            continue;
 309         }
 310         track_id &= 0x3f;
 311         idx = get_sindex(s, track_id, track_type);
 312         if (idx < 0) continue;
 313         st = s->streams[idx];
 314         if (!main_timebase.num || !main_timebase.den) {
 315             main_timebase.num = si.frames_per_second.den;
 316             main_timebase.den = si.frames_per_second.num * si.fields_per_frame;
 317         }
 318         st->start_time = si.first_field;
 319         if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
 320             st->duration = si.last_field - si.first_field;
 321     }
 322     if (len < 0)
 323         av_log(s, AV_LOG_ERROR, "invalid track description length specified\n");
 324     if (map_len)
 325         url_fskip(pb, map_len);
 326     if (!parse_packet_header(pb, &pkt_type, &len)) {
 327         av_log(s, AV_LOG_ERROR, "sync lost in header\n");
 328         return -1;
 329     }
 330     if (pkt_type == PKT_FLT) {
 331         gxf_read_index(s, len);
 332         if (!parse_packet_header(pb, &pkt_type, &len)) {
 333             av_log(s, AV_LOG_ERROR, "sync lost in header\n");
 334             return -1;
 335         }
 336     }
 337     if (pkt_type == PKT_UMF) {
 338         if (len >= 0x39) {
 339             AVRational fps;
 340             len -= 0x39;
 341             url_fskip(pb, 5); // preamble
 342             url_fskip(pb, 0x30); // payload description
 343             fps = fps_umf2avr(get_le32(pb));
 344             if (!main_timebase.num || !main_timebase.den) {
 345                 // this may not always be correct, but simply the best we can get
 346                 main_timebase.num = fps.den;
 347                 main_timebase.den = fps.num;
 348             }
 349         } else
 350             av_log(s, AV_LOG_INFO, "UMF packet too short\n");
 351     } else
 352         av_log(s, AV_LOG_INFO, "UMF packet missing\n");
 353     url_fskip(pb, len);
 354     if (!main_timebase.num || !main_timebase.den)
 355         main_timebase = (AVRational){1, 50}; // set some arbitrary fallback
 356     for (i = 0; i < s->nb_streams; i++) {
 357         AVStream *st = s->streams[i];
 358         av_set_pts_info(st, 32, main_timebase.num, main_timebase.den);
 359     }
 360     return 0;
 361 }
 362
 363 #define READ_ONE() \
 364     { \
 365         if (!max_interval-- || url_feof(pb)) \
 366             goto out; \
 367         tmp = tmp << 8 | get_byte(pb); \
 368     }
 369
 370 /**
 371  * \brief resync the stream on the next media packet with specified properties
 372  * \param max_interval how many bytes to search for matching packet at most
 373  * \param track track id the media packet must belong to, -1 for any
 374  * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
 375  * \return timestamp of packet found
 376  */
 377 static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
 378     uint32_t tmp;
 379     uint64_t last_pos;
 380     uint64_t last_found_pos = 0;
 381     int cur_track;
 382     int64_t cur_timestamp = AV_NOPTS_VALUE;
 383     int len;
 384     ByteIOContext *pb = s->pb;
 385     GXFPktType type;
 386     tmp = get_be32(pb);
 387 start:
 388     while (tmp)
 389         READ_ONE();
 390     READ_ONE();
 391     if (tmp != 1)
 392         goto start;
 393     last_pos = url_ftell(pb);
 394     url_fseek(pb, -5, SEEK_CUR);
 395     if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
 396         url_fseek(pb, last_pos, SEEK_SET);
 397         goto start;
 398     }
 399     get_byte(pb);
 400     cur_track = get_byte(pb);
 401     cur_timestamp = get_be32(pb);
 402     last_found_pos = url_ftell(pb) - 16 - 6;
 403     if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
 404         url_fseek(pb, last_pos, SEEK_SET);
 405         goto start;
 406     }
 407 out:
 408     if (last_found_pos)
 409         url_fseek(pb, last_found_pos, SEEK_SET);
 410     return cur_timestamp;
 411 }
 412
 413 static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
 414     ByteIOContext *pb = s->pb;
 415     GXFPktType pkt_type;
 416     int pkt_len;
 417     while (!url_feof(pb)) {
 418         AVStream *st;
 419         int track_type, track_id, ret;
 420         int field_nr, field_info, skip = 0;
 421         int stream_index;
 422         if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
 423             if (!url_feof(pb))
 424                 av_log(s, AV_LOG_ERROR, "sync lost\n");
 425             return -1;
 426         }
 427         if (pkt_type == PKT_FLT) {
 428             gxf_read_index(s, pkt_len);
 429             continue;
 430         }
 431         if (pkt_type != PKT_MEDIA) {
 432             url_fskip(pb, pkt_len);
 433             continue;
 434         }
 435         if (pkt_len < 16) {
 436             av_log(s, AV_LOG_ERROR, "invalid media packet length\n");
 437             continue;
 438         }
 439         pkt_len -= 16;
 440         track_type = get_byte(pb);
 441         track_id = get_byte(pb);
 442         stream_index = get_sindex(s, track_id, track_type);
 443         if (stream_index < 0)
 444             return stream_index;
 445         st = s->streams[stream_index];
 446         field_nr = get_be32(pb);
 447         field_info = get_be32(pb);
 448         get_be32(pb); // "timeline" field number
 449         get_byte(pb); // flags
 450         get_byte(pb); // reserved
 451         if (st->codec->codec_id == CODEC_ID_PCM_S24LE ||
 452             st->codec->codec_id == CODEC_ID_PCM_S16LE) {
 453             int first = field_info >> 16;
 454             int last  = field_info & 0xffff; // last is exclusive
 455             int bps = av_get_bits_per_sample(st->codec->codec_id)>>3;
 456             if (first <= last && last*bps <= pkt_len) {
 457                 url_fskip(pb, first*bps);
 458                 skip = pkt_len - last*bps;
 459                 pkt_len = (last-first)*bps;
 460             } else
 461                 av_log(s, AV_LOG_ERROR, "invalid first and last sample values\n");
 462         }
 463         ret = av_get_packet(pb, pkt, pkt_len);
 464         if (skip)
 465             url_fskip(pb, skip);
 466         pkt->stream_index = stream_index;
 467         pkt->dts = field_nr;
 468         return ret;
 469     }
 470     return AVERROR(EIO);
 471 }
 472
 473 static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
 474     uint64_t pos;
 475     uint64_t maxlen = 100 * 1024 * 1024;
 476     AVStream *st = s->streams[0];
 477     int64_t start_time = s->streams[stream_index]->start_time;
 478     int64_t found;
 479     int idx;
 480     if (timestamp < start_time) timestamp = start_time;
 481     idx = av_index_search_timestamp(st, timestamp - start_time,
 482                                     AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
 483     if (idx < 0)
 484         return -1;
 485     pos = st->index_entries[idx].pos;
 486     if (idx < st->nb_index_entries - 2)
 487         maxlen = st->index_entries[idx + 2].pos - pos;
 488     maxlen = FFMAX(maxlen, 200 * 1024);
 489     url_fseek(s->pb, pos, SEEK_SET);
 490     found = gxf_resync_media(s, maxlen, -1, timestamp);
 491     if (FFABS(found - timestamp) > 4)
 492         return -1;
 493     return 0;
 494 }
 495
 496 static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
 497                                   int64_t *pos, int64_t pos_limit) {
 498     ByteIOContext *pb = s->pb;
 499     int64_t res;
 500     url_fseek(pb, *pos, SEEK_SET);
 501     res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
 502     *pos = url_ftell(pb);
 503     return res;
 504 }
 505
 506 AVInputFormat gxf_demuxer = {
 507     "gxf",
 508     NULL_IF_CONFIG_SMALL("GXF format"),
 509     0,
 510     gxf_probe,
 511     gxf_header,
 512     gxf_packet,
 513     NULL,
 514     gxf_seek,
 515     gxf_read_timestamp,
 516 };